Most plants store oil and fat in their seeds, with triacylglycerol being more predominant than other oil and fat forms. In plants, the first energy product is in the form of carbohydrate which are later converted and stored into triacylglycerol, a more dense form. Upon germination, 1 g of the stored oil is converted into 2.7 g of carbohydrate, which is directly used as an energy source during germination.
Vegetable oils are more abundant in unsaturated fatty acids compared to animal oils, and plants contain 18:2 and 18:3 fatty acids, and polyunsaturated derivatives thereof, which cannot be synthesized in animals. These fatty acids are called essential fatty acids, since they cannot be synthesized in vivo, and thus could be only ingested through food. In addition to the importance as food, vegetable oils are emerging as an alternative energy source, with extensive attention being paid as biodiesel due to the recent exhaustion of fossil fuel.
The production of oilseeds in the world amounted to 3.19 billion metric tons in 2001. While some are used directly as food, most of them are used for oil extraction. On average, the content of oil in oilseed accounts for roughly 26% of its total weight. Globally, the consumption of animal oil has been decreased or maintained since in 1970, while the consumption of vegetable oil has more than coupled between 1980 and 2000 (ca. 670 million tons), with a rapid increase in consumption tendency (refer to USDA food disappearance records, U.S. PUFA Consumption, 1909-2005).
As can be seen, the demand for vegetable oils tends to increase as days go by, while supply can't catch up the demand. To date, the output of oils from oilseeds has been maximized thanks to the continuous improvement in breeding and crossbreeding, and it is anticipated that with the current breeding and crossbreeding, it is difficult to catch up the demand in a limited cultivation area. As a solution to this limitation, genetically modified organisms have come to the fore. For the production of vegetable oil which is expected for tremendous worldwide demand, it is anticipated that developing genetically modified organisms with high oil output is essential. In this regard, many researchers around the globe are conducting research on increasing the oil content per unit weight of seed and increasing the total amount of oil, but many genes are complicatedly involved in triacylglycerol synthesis in the seed and the control process which take up most of the stored vegetable oil, and thus, the goal isn't being accomplished easily.
In order to improve the stored oil of plant seed, big multinational corporations, such as Monsanto and DuPont are conducting a research. But yet, accomplishments haven't been reported since although a fat content of a seed increases, there are lots of cases when the overall productivity decreases due to the reduction of overall plant growth and the number of silique. There is therefore a need to develop a gene that functions to allow an increase in oil content in a seed that mostly stores the vegetable oil, without decreasing the size of seeds or the number of siliques, or more ideally, increases both the size of seeds and the number of siliques. If this technology is developed, it can create higher values when applied in conjunction with other technologies developed in regards of plant fats. For example, the technology can be used to produce a greater amount of useful fats when it is applied to a plant producing omega-3 fatty acids or tocopherol or a certain useful fat/fatty acids, together with a technique of increasing the size of seeds and the number of siliques.